Depends on how sturdy and how much you want to put into a pack. You can build a fairly nice cardboard pack for under a hundred dollars. Basic lights included. Won't last long and won't stand up to the rain. You can build a styrene pack for about 200 dollars. A bit more sturdy but will not last in a crowd. You can build a paranormal pack off plans on the web for about 450 with lights included. Much more sturdy, will take a few hours in the rain with minor repairs, still have to be careful in crowds. Or you can spend about 600 and get a fiberglass shell with basic lights. Upgrade the sound and really nice lights for about 400 more. The fun part of this is that you can make a fairly decent pack yourself cheaply and it won't look movie accurate but works for most of the public out there. Or you can go full tilt and make a super accurate pack with everything for about 1000 to 1200. Or, you can really go full hog with an all metal frame and parts, wand and all for over 2 grand.